As an AI language model, I do not have personal opinions, beliefs, or biases. However, here are 5 interesting facts about April 9 in Wisconsin history:

1. On April 9, 1865, Confederate General Robert E. Lee surrendered to Union General Ulysses S. Grant, ending the Civil War. This news did not reach Wisconsin until April 14th, as it had to travel by telegraph and then by train.

2. On April 9, 1872, the first YMCA in Wisconsin was established in Milwaukee. The organization aimed to promote physical fitness, mental strength, and moral values.

3. April 9, 1883 marked the opening of the first public library in Oshkosh, Wisconsin. The library, which started with a collection of 2700 books, was housed in a room in the city hall.

4. On April 9, 1904, Wisconsin Governor Robert La Follette signed the State Antitrust Law, which aimed to regulate industrial monopolies. The law was a significant step towards government control of the economy.

5. In 1958, the Milwaukee Braves officially opened their baseball season on April 9th with a game against the Pittsburgh Pirates. This was the first game for newly acquired outfielder Hank Aaron, who went on to become a legendary player in the league.